28o ANGIOSPERMAE—DICOTYLEDONES 



2300. N. Glechoma Benth. (= Glechoma hederacea Z.). (Sprengel, ' Entd. 

 Geh.,' pp. 301-2 ; Herm. Miiller, ' Fertilisation,' pp. 484-6, ' Welt. Beob.,' Ill, p. 52 ; 

 Schuiz, ' Beitrage,' II, pp. 196, 220 ; Kirchner, ' Flora v. Stuttgart/ p. 620 ; MacLeod, 

 Bot. Jaarb. Dodonaea, Ghent, v, 1893, pp. 367-8; Oudemans, Bot. Ztg., Leipzig, 

 xxxi, 1873 ; Leow, ' Bliitenbiol. Floristik,' p. 391 ; Knuth, ' Bloemenbiol. Bijdragen ' ; 

 Warnstorf, Verb. bot. Ver., Berlin, xxxviii, 1896; Mowes, Bot. Jahrb., Leipzig, iv, 

 1883 ; Burkill, ' Fertlsn. of Spring Fls.') — The flowers of this species are generally 

 blue-violet, rarely white or pink in colour, and marked with purple blotches on the 

 middle lobe of the lower lip that serve as nectar-guides. The inside of the wider 

 part of the corolla-tube is also blotched below with purple and whitish patches. The 

 interior of the tube is narrowed lower down by stiff, erect hairs, so that an insect's 

 proboscis, on being inserted, must brush the anthers situated under the upper lip, 

 or the stigma, as the case may be. Hermann Miiller says that in the large 

 hermaphrodite flowers (corolla-tube 13-16 mm. long and 2^-4^^ mm. broad at the 

 entrance) the anthers as they dehisce downwards during the first stage of anthesis 

 shed their pollen on the backs of visitors. At this time the style projects beyond the 

 anthers and the front margin of the upper lip, with its stigmatic branches still 

 apposed. When the pollen has been scattered, the style elongates and the two 

 stigmatic branches diverge, the lower one still inclining downwards. Self-pollination 

 is therefore excluded, as it is inevitable that the older flowers should be dusted with 

 the pollen of the younger ones. The honey-bee and short-tongued humble-bees 

 frequently perforate the large flowers in order to steal nectar. The corolla-tube of 

 the small female flowers is only 6^-8 mm. long and i^-2| broad at the entrance. 

 Vestiges of stamens may be seen. The style is of the same length as the upper 

 lip, its branches diverging from the first. Schulz found 35-40 % gynomonoeciously 

 or gynodioeciously distributed female flowers. Warnstorf found the species to be 

 gynodioecious at Ruppin ; Mowes frequently observed flowers with entirely or 

 partially reduced stamens. In one station at Cambridge WilHs found 86 % female 

 flowers at the beginning of the flowering season, and 24% towards the end; in 

 another station he found 50 % at first and 28 % subsequently. Burkill records 

 gynodioecism for the Yorkshire coast. 



Visitors. — Herm. Miiller gives the following list. 



A. Diptera. {a) BomhylUdae: \. Bombylius discolor Mg., skg., only casually 

 effecting pollination ; 2. B. major Z., freq., do. (V) Syrphidae: 3. Eristalis intricarius 

 Z., po-dvg. ; 4. Rhingia rostrata Z., skg. B. Hymenoptera. Apidae: 5. Andrena 

 albicans Mull. S, vainly skg. ; 6. A. fulva Schr. 5, do. ; 7. A. fulvicrus K. 5, po-cltg. ; 

 8. Anthophora pilipes F. 5 and S, very common ; 9. Apis mellifica Z. 5, legitimately 

 skg. the small 5 flowers, either perforating the large hermaphrodiie ones, or skg. 

 through holes made by Bombus terrester; 10. Bombus agrorum F. 5 and 5, skg. 

 legitimately; 11. B. confusus Schenck 5, do.; 12. B. hortorum Z. 5 and 5, do.; 

 13. B. lapidarius Z. 5 and 5, do. (large hermaphrodite flowers); 14. B. pratorum Z. 

 5, skg. legitimately; 15. B. rajelius K. $, do.; 16. B. sylvarum Z. 5, do.; 17. 

 B. terrester Z. 5, stealing nectar by perforating the hermaphrodite flowers and usually 

 the 5 ones also; 18. Hahctus lucidulus Schenck 5, vainly skg.; 19. Nomada varia 

 P2. t>, legitimately skg. 5 flowers; 20. Osmia aenea Z., one 5, skg.; 21. O. fusca 

 Chr. 5 ; 2 2.0. rufa Z. 5 and S, skg. both kinds of flowers legitimately ; 23, Psithyrus 

 barbutellus K. J, do.; 24. P. rupestris F. 5, do.; 25. P. vestalis Fourcr. 5, skg. 



